Process for the extraction of platinum and similar metals from their sands and ores.



RUSSELL UPI-EATER, PHILADELPHIA. PENNSYLVANIA.

PROCESS FOR THE EXTRACTION 01? PLATINUM AND SI-MILAJBL METALS FROM SANDS AND ()ltES.

H Drawing.

5f '0 all whom it may concern Be it known that l, llnss'ni ii Trmi'nn, of

Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Processes for the Extraction of Platinum and Similar Metals from Their Sands and Ores, whereof the following is a specification;

The invention is addressed to the re covery of the finely divided platinum, or similar metals, which may exist in such sands or ores initially in a free condition, or which may be released therein as the result of fine grinding-of the enveloping gangue.

I have discovered that notwithstanding the extremely high meltin point of platinum and the rare metals of this group, and their relatively high specific gravity, they can, when in an exceedingly con'nninuted condition, "be volatilized under the effects of heat,and, by the use of a proper vehicle, can be carried away from the sands or ores in which they are contained, and I have also discovered the further fact that the volatilized particles, when carried away, can be detained or-suspended in water, so as to separate them from any vehicle which may be employed as an adjunct in the volatilization.

ll will now describe a preferred embodi ment of my invention as applied to the recovery of platinum, it being understood that l do not thereby restrict myself to the recovery of that particular metal alone.

I take a body of sand or ore of such cubic content as to be conveniently treated in a retort of reasonable size and preferably grind the sands or ore very fine, say to about two hundred mesh. The degree of fineness of grinding will depend upon the character of the sands or ore and their metallic c on tent. In many cases but slight grinding is necessary, suilicient to release the metallic particles from the sands or rock particles. lit will therefore be understood that the primary purpose of the grinding is not to reduce the size of the metallic particles themselves, since ordinarily they occur in nature in an exceedingly comminuted condition, but is addressed mainly to their dis- """en,e;;.i.gement from the containing envelop.

, ll intimately mix with the sand or ore a quantity of metallic mercury to which me- Specification of Letters Patent. Pmlgmyitpdl July 23, yams, Application filed August 15, 1917.

Serial No. 1%,303.

tallic sodium has been added. This is preferably done during the grinding process, and Water may be added, preferably to an extent just sufficient to thorou 'hly moisten the mass. As soon' as the grinding andadmixture of the mercury Tis complete, the magma is placed in a retort suliiciently to cause the evaporation of the mercury by actual distillation. Thedischarge from the retort is conducted into a body of Water wherein the mercury is con: densed and falls to the bottom. The errceedingly fine particles of platinum, however, notwithstanding the relatively high specific gravity of the metal itself, Will remain suspended in the Water for a considerable time. "Whether; thisphenomenon is due to some peculiar conditions of surface tension of the particles, or to some other factor characteristic of the conditions in which they occur in sands and like bodies,

l have not as yet definitely determined, but the suspension, or detention, of the platinum particles is so definite and so prolonged as to effectually separate them from the mercury particles, by which I believe them to have been in a certain sense conveyed in the act of volatilization. The treatment is continued until it becomes manifest that no more platinum is coming over. The Water in which the particles from the retort, have been received, is their decanted from the mercury and is filtered, referably by means of an ordinary paperhlter.

The filter is then dried slowly and burned in confinement, under such conditions as not to permit the cai-ry'ing'a'way of any of the finely divided platinum. The ash may then be treated with aqua regia, and the platinum recovered in any convenient Way from the resultant c01npound.

If desired, the mercury may be employed alone without the addition of sodium, or any other alkalimetal may be employed in combination with the mercury together with, or in place of, the sodium.

Having thus described my process in its preferred embodiment, ll desire to state that l do not limit myself to the employment of a metallic vehicle as an adjunct to assist in the volatilization, since I believe that to some extent the phenomenon Will occur, even when aqueous vapor, or a, gas, is properly employed as a vehicle or draft-producing current. Thave found, however, that mer- "and heated eury 1 tain avidity therefor, which is manifested by the actual picking up and temporary detention of platinum especially when finely divided by a body of mercuryf This avidity appears to be greatly intensified when the mercury is combined with sodium or other similar. alkali metal and applied in the presence of Water. Y

My belief is thatunder the circumstances above set forth, the mercury, when vaporized by distillation, carries along with it the minute particles of platinum, which it has thus picked up, and I have described the phenomenon as volatilization of the platinum, in solid form, asdistinguished from the change of physical condition which would be implied by the term vaporization.

Whatever may be the explanation, I have found it to be the fact that platinum can be thus separated and recovered from ore in a manner available for commercial metallurgical practice, and I believe that my process can be made available for obtaining platinum from ores and sands, which heretofore have been considerea not practically useful as a source thereof. I believe that the phenomenon is characteristic of some of the so-called num group, sue for instance, as iridium, which is usually found in association with platinum, and I therefore do not limit my claims to the recovery of platinum alone, but desire to compre end the recovery of such other metals, which 1 term similar, in the sense that they belong to the platinum group, and while they have a high melting point and high specific gravity comparable to those of platinum, are capable of volatilization when in a finely divided form.

Having thus described my invention, I

claim:

1. The hereinbefore described process of recovering finely divided platinum and similar metals from sands orore, which consists in volatilizing the finely divided metallic floplea of this patent may be recious metals of the pla'tiparticles by heat, at a temperature below the melting point of the metal; carrying away the volatilized particles by a suitable vehicle; and collecting the volatilized particles.

Q. The hercinbetore described process of recovering finely divided platinum and similar metals from sands or ore, which consists in mixing-the sands or ore with metallic mercury; subjecting the magma to a temperature sufiicient to distil the mercury, but below the melting point of the platinum or similar metal; collecting the distilled mercury and volatilized platinum or similar metal; and separating the platinum or similar metal from the mercury. v

3. The hereinbet'ore described process of recovering finely divided platinum and similar metals from sands or ore, which consists in mixing the sands or orc with metallic mercury and an alkali metal; subjecting the magma to a temperature sufilcient to distil the mercury, but below the meltingpoint of the platinum or similar metal; collecting the distilled mercury and \olatilized platinum or similar metal; and separating the platinum or similar metal from the mereury.

l. The hereinbelore described process of recovering finely divided platinum and similar metals from sands or ore, which consists in mixing the sands or ore with metallic mercury; subjecting the magma to a temperature sufiicient to distil the mercury, but below the melting point of the platinum or similar metal; collecting the mercury and platinum or similar metal in water; separating the mercury; collecting the platinum or similar metal by filtration; and recovering the platinum or similar metal from the filter residium.

In testimony whereof, I have her unto signed my name at Philadelphia, P sylvania, this eighth day of August, 19 Z.

RUSSELL THAYER. Witnesses:

J AMES H. BELL, A. Item.

obtained for flv cents each, by addressing the Commissioner of Patents.

Wanhington, D. O. 

